Verse 5 in Yājuṣa-Jyotiṣa ("Mīnāt prabhṛti Raśayaḥ") and Verse 4 of Ārcha-Jyotiṣa are the earliest direct references to Raśi in ancient literature.

Atharva-Jyotiṣa is most detailed of these three texts, and gives detailed proofs pf phalita (predictive) Jyotiṣa in the Vedic period. Yajñas were performed for obtaining "phala". But only a tip of the iceberg has survived : verse 3 of Ārcha-Jyotiṣa says the motions of heavenly bodies are "completely" described in Ārcha-Jyotiṣa, but only 36 verses are extant now.

पौराणिक और महाकाव्य साहित्य में ज्योतिष

'Sarga' is an essential chapter in every Purāna, which describes the process and mathematics of Creation and Yuga-cycles, which are common to all ancient siddhāntas of Jyotiṣa. Some Purānas provide greater details about mathematical portions of Jyotiṣa, while important aspects and rules of Phalita Jyotiṣa and Parvādi are scattered in various Purānas. Nārada Purāna devoted greatest space to Jyotiṣa. Mahābhārata and Rāmāyana also contain many references to and uses of Jyotiṣa. For instance, Mahābhārata refers to the use of Sarvato-Bhadra Chakra which is an astrological tool fully described in ancient Yāmala Tantra literarure.

जैन साहित्य में ज्योतिष

मध्ययुगीन ज्योतिष ग्रन्थ

आधुनिक ज्योतिष ग्रन्थ

उपलब्ध मौलिक ग्रन्थ

The main phalita text of Jyotiṣa is the Brihat Pārāshara Horā Shāstra (BPHS), originally called Pārāshari Horā, which belongs to the last phase of Dvāpara Age. Four chapters of Jaimini Sutra have also survived. Extant portions of Lomasha Samhitā and some other texts are also helpful in Horā, but BPHS remains the mainstay of Phalita. The most revered siddhāntic text of Jyotiṣa is Suryasiddhānta which states it was given by Lord Surya at the tail end of Krit Yuga. The earliest paurusheya (man-made) texts of Jyotiṣa , such as Panchsiddhāntika by Varāha Mihira, eulogize Suryasiddhānta as divine. There is a verse in Charana-vyuha which says that there were one lakh verses in Veda (only 20% has survived), one lakh is Mahābhārata (almost entirely survived), one lakh in Vyākarana (mostly lost) and four lakhs in Jyotiṣa. But even the magnum opum of Phalita Jyotiṣa, namely BPHS (Brihat Pārāshara Horā Shāstra) contains only four thousand (it is suspected to contain over ten thousand verses originally). Charana-vyuha is an ancient work and we have few texts of Jyotiṣa surviving from that time, and most of those surviving texts have been mutilated and distorted. Yet, enough remains to enable a person becoming a reasonably good astrologer according to modern standards, provided the conditions mentioned in BPHS for becoming a good astrologer are fulfilled : deft in Ganita and Horā as well as in Sanskrit grammar and Nyāya, intelligent, capable of deriving good inductions and deductions, knower of Desha and Kāla, and Jitendriya (brahmachāri). Few astrologers fulfill these conditions laid down by Sage Parāshara.

आधारभूत अवधारणाएँ और पारिभाषिक शब्दावली

काल-प्रणाली

How to measure Time depends on the purpose for which we need to measure Time. Hence, there are various Time-Systems.

काल-प्रणाली के प्रकार

युगचक्र

काल के अवयव

Month : Solar and Lunar

Ahorātra

Ahorātra means the time from one Sunrise to next Sunrise at a given place on the surface of Earth. Literally, it means Day plus Night. It is not exactly equal to 24 hours, because Sunrise varies from day to day, while the modern measure of 'hour' is a constant defined on the basis of Atomic definition of a 'second' of time.

Ghati or Danda

ग्रह और उनके लक्षण

पञ्चांग

Moon is the fastest planet. Hence, elements related to motions of Moon are accorded highest priority in a religious almanac known as Panchānga (= "Five limbs") : Tithi, Karana, Rāsi, Nakshatra and Vāra.

तिथि

Tithi is Moon's Elongation or angular distance from Sun ; 12 degrees of elongation is equated to one tithi and 360 degrees or one full circle is one Luni-Solar Month, or in short Lunar Month of Hindus (Chāndra-māsa). Counting of tithis begin from New Moon to next New Moon, but counting of Luni-Solar months start and end with Full Moon, as the term "Poorna-māsi" implies. This system existed even in earliest Vedic era, as the very name of first Vedic yajna "Darshapoornamāsi" implies : Darsha means New Moon and Poorna-māsi means Completion of Month on Full Moon.

करण

Karana is a subsidiary of Tithi, defined as exact half of a tithi.

राशि

Rasi and Nakshatra are interrelated and depend solely on Moon's absolute motion with respect to Fixed Sky.

नक्षत्र

वार

Vāra is not a feature of Moon, but of Sun, and depends on topocentric Sunrise for a given place at earth's surface.

पञ्चांग के अन्यान्य अवयव

पञ्चांग कैसे देखें

पञ्चांग के विषय और उपयोग

The word Panchānga means "Five limbs", i.e., Tithi, Karana, Nakshatra, Yoga and Vāra. All these five elements depend on motions of Moon and Sun and require high degree of accuracy due to fast motion of Moon. Moreover, these elements exert greater astrological influence than other planets. That is why religious almanac has come be labeled as 'Panchānga'. But a Panchānga should contain planetary data and table of ascendants for facilitating handy computation of horoscopes, and religious festivals and muhurtas (auspicious moments for diverse activities) are also provided in a normal Panchānga. A good Panchānga contains much extra related information as well and is published once a year. Beginning of religious year for publishing Panchāngas is not same for entire India, but beginning of white half of Chaitra is generally accepted as the start of religious (and traditional calendar) year by most Hindus. Sun's entry into nirayana (sidereal) Mesha is the mathematical New Year of Hindus.

पञ्चांग बनाने की विधियों की बहुलता पर विवाद

अन्य महत्वपूर्ण अवधारणाएँ और शब्दावली

ज्योतिष के विभाग

Vedic Jyotiṣa has two branches, Ganita (Siddhānta) and Phalita (Samhitā plus Horā). Ganita means mathematics, but in practice it does not include the calculations involved in making horoscopes and predictions, it is merely a synonym for Siddhānta in the parlance of traditional jyotishis. Phalita or predictive astrology has two main branches, Samhitā and Horā, which have many sub-branches as shown below. But in actual practice, Samhitā and Horā are enumerated as separate branches due to vast difference in their subject matter, and traditional taxonomy talks of three skandhas or divisions of Jyotiṣa : Siddhānta, Horā and Samhitā, and every good Jyotiṣi was expected to be adept in all three divisions of Tri-skandha Jyotiṣa-shāstra.

Siddhānta, which literally means "theory" (siddha+anta", ie "established conclusions") is traditional astronomy for special uses of astrology, which has many varieties broadly divided into two classes apaurusheya and paurusheya on whose basis later Tantra and Karana texts were derived.

Original apaurusheya Siddhāntas, 18 in number, propounded by sages or gods

Man-made or paurusheya siddhāntas, five ancient siddhāntas and another set of five later siddhāntas now used by traditional panchānga (a panchānga is the calendar or religious almanac makers).

Tantra (astrological) method and texts, different from philosophical Tantra

Karana method and texts

Drig-ganita or physical astronomy

Samhita , which includes :

Medini Jyotiṣa (mundane astrology) or predictive astrology of territorial regions and is used for predicting important events such as earthquakes, weather events like storms or rains, war, national politics and economy, prices (argha-kānda), etc, based on analysis of astrological dynamics in the horoscope of a territorial region of all sizes including whole world, and/or general transit events (graha-chāra).

84 Chakras (astrological) which are widely used in Medini Jyotiṣa as well as in Horā, such as Panch-shalākā or Sarvatobhadra chakras which originated in archaic Yāmala Tantras.

Vāstu-shāstra which is used for construction of houses, temples, forts and towns. Varāha Mihira included iconography and sculpture under Samhitā.

Shakuna-shāstra (omens)

Diverse topics like astrological and similar attributes of materials, trees, animals, regal attributes and items, etc.

Horā : predictive astrology of individuals, whose main branch is called Jātaka.

Jātaka which is used to analyze natal horoscopes (birth charts) known as janma-kundali. It includes Varshaphala. One of its branch Nasta-Jātaka studies those persons whose birth details are unknown.

Prashna (horary astrology) from which horoscopes based on the moment and a query are made. Prashna is also used to make hosocopes without birthdata in Nasta-Jātaka.

Sāmudrika shāstra studies palmistry, mukhākriti-vijnānam or study of facial features, anga-lakshanam or features of different parts of body, etc and correlate these things with planets of horoscopes.

Svara-shāstra

Strictly speaking, Horā-shāstra is based on birth time of the native and therefore Jātaka is the only true branch of Horā, but Prashna, Sāmudrika and Svara-shāstra are helpful in Horā esp when birth time is unknown. Even when birth time in known these disciplines help in removing errors and arriving at greater and better details.

सिद्धान्त

Ganita or Siddhānta skandha (branch) of Jyotisha is traditionally sub-divided into three sub-branches :

सिद्धान्त

It provides planetary calculations together all requisite formulas and their geometry from the beginning of Creation and provides details of all periods and sub-periods of entire Kalpa or Day of Lord Brahmā of 4.32 billion years, of which 1,955,885,111 years (in 2011 AD) have elapsed since the beginning of present Creation. In actual practice, no siddhānta is directly used for panchangas or horoscopes, because it is very difficult to make each and every computation from the beginning of Creation. Siddhānta is used only for creating Tantra and Karana texts for practical purposes.

तन्त्र

When planetary positions at the onset of current Yuga are tabulated and computations for succeeding years are made on the basis of these tables, the technique is called Tantra in Jyotisha. It has nothing to do with Tantra of philosophy. The only available Tantra text is Soma-Siddhānta which gives calculations from the beginning of Kaliyuga. Extant version of Surya-Siddhānta enables one to make computations from the beginning of Creation, but also gives planetary positions at the end of recent Krit Yuga (beginning of Tretā Yuga), hence it provided Tretā Yuga's Tantra method as well.

करण

When starting point of Kaliyuga receded, Tantra method became difficult to use and Karana texts were created which used same method from some nearby year. Most famous Suryasiddhāntic Karana text is Makaranda Sārani, made for Shaka 1400 or 1478 AD. Its siddhantic version automatically updated for all eras is available in the form of free softwares : Kundalee and JHora-7.52 beta2 (constantly being updated).

प्रारम्भिक 18 सिद्धांत

Mahabharata (1.70.43) defined siddhānta as "siddha-paksha-sthāpanam", i.e., establisheg the proven theory. It is said there were 18 ancient siddhāntas, but when ancient siddhāntas are enumerated from diverse sources excluding all texts after 400 AD, the list crosses 18 :

1. Brahma-siddhānta or Pitāmaha

2. Surya-siddhānta

3. Soma-siddhānta

4. Brihaspai-siddhānta

5. Garga-siddhānta

6. Nārada-siddhānta

7. Parāshara-siddhānta

8. Paulastya-siddhānta

9. Vasishtha-siddhānta

10. Vyāsa-siddhānta

11. Atri-siddhānta

12. Kashyapa-siddhānta

13. Marichi-siddhānta

14. Manu-siddhānta

15. Angirasa-siddhānta

16. Lomasha-siddhānta

17. Pulisha-siddhānta

18. Bhrigu-siddhānta

19. Shaunaka-siddhānta (Soma-siddhānta ?)

20. Chyavana-siddhānta

21. Yavana-siddhānta

Soma-Siddhānta is a Tantra variety of Surya-Siddhānta. Narada Purana gives details of planetary calculations which are perfectly in harmony with Surya-Siddhānta. Shaunka Horā states that Kaushika Viswāmitra learned accurate astronomy from Maya who first got Surya-Siddhānta. Shaunaka-Siddhānta is stated by some to be same as Soma-Siddhānta. Yavana-Siddhānta cannot be included among archaic Siddhāntas given by rishis or gods. Omitting Yavana-Siddhānta from the list and considering two Siddhāntas to be mere synonymns of other siddhāntas, the list can be reduced to the customary number 18. It is wrong to assume that there were 18 different Siddhāntas warring against each other. There was only one Siddhānta received by sages in different eras. As Surya-siddhānta states (chapter-1, verse-9), same Surya-siddhānta was given with "Kālabheda" in different eras. Varāha Mihira says Surya-siddhānta is the Siddhānta of Vedic god Savitā. At present, Surya-Siddhānta and Soma-Siddhānta are available in full, the latter being a Tantra version of the former, and Nārada-Siddhānta is available in some detail in Nārada Purana, which shows no difference with Surya-siddhānta. Brahma-Siddhānta is said to emanate from Lord Brahmā and is available in some detail in Brahma Vaivarta Purana, but shows no difference with Surya-Siddhānta. All other Siddhāntas have been completely lost because they were no longer needed, as is the case with Soma-siddhānta which was useful during initial centuries of Kaliyuga as its formulations prove but nobody touches it now. Hence, Surya-Siddhānta seems to be the basis of all Siddhāntas which were Tāntric manifestations of same Surya-siddhānta for different eras with respective beeja-samskāras.

वराहमिहिर की पञ्चसिद्धान्तिका में पांच प्राचीन सिद्धांत

In his treatise Panchsiddhāntikā, Varāha Mihira mentions five Siddhāntas available in his era : Surya-Siddhānta, Paulisha-Siddhānta, Romaka-Siddhānta of yavanas, Paitamaha-Siddhānta and Vasishtha-Siddhānta, last two declared by him to be of no use in their extant forms, Surya-Siddhānta being the best. In Brihat Samhita too, Varāaha Mihira said that he used Surya-Siddhānta for computations.

परम्परावादी पंचांगकारों द्वारा प्रयुक्त पांच आधुनिक सिद्धांत

All traditional panchanga makers use either of the following five Siddhāntas directly or indirectly : Surya-Siddhānta, Brahma-Sphuta Siddhānta of Brahmagupta, two Arya Siddhāntas of two Aryabhatas and Mahā-bhāskareeya of Bhāskara-i. Of these, Surya-Siddhānta is the only apaurusheya ancient text, others being beeja corrected versions made during 600-900 AD.

सूर्यसिद्धांत की अन्य सिद्धांतों से तुलना

सूर्यसिद्धांत बनाम दृकसिद्धांत विवाद

बीज-संस्कार

In the chapter on Mean Motions (verse-9) in Surya-Siddhānta, it is said that this siddānta is given by Lord Surya in different eras with Kāla-bheda, ie, with differences depending on Time. These differences must be in mean motions as the chapter's name suggests. Traditionally, such a difference is called "beeja-samskāra". Revolutions of a planet per Mahāyuga is called Yuga-bhagana. Texts give Yuga-bhagana in integers and fractional portion of Yuga-bhagana is added as beeja-samskāra. Makaranda-Vivarana by Daivajna Diwakara (17th century) gives the quantitative values of beeja-samskāra os various planets which were used in constructing Makaranda Tables in 1478 AD according to Surya-Siddhānta ("Shri Surya-Siddhānta matena…"). Unfortunately, many moderners not acquainted with traditional methods of panchānga makers now say that Surya-Siddhānta later became outdated and therefore beeja-samskāra was later introduced. Such a view is erroneous, because Surya-Siddhānta was never in conformity with physical astronomy and the divergence increases as we go back into past. Even after introducing beeja-samskāra, siddhāntic planetary positions do not come near to physical planets for any period of history. Ancients knew this problem. Vishni-dharmottara Purāna says : यन्त्रवेधादिना ज्ञातं यद्-बीजं गणकैस्ततः । ग्रहणादि परीक्षेत न तिथ्यादि कदाचन ।। I.e, for viewing eclipses &c, compute beeja according to observations from instruments &c, but never use this method for tithyādi. Nirnaya-sindhu, a respected text of Dharma-shāstra, also says : अदृष्टफलसिध्यर्थ यथार्कगणितं कुरु । गणितं यदि दृष्टार्थ तद्-दृष्ट्युद्भवस्सदा ।। I.e, use Surya-Siddhānta for getting astrological results. Surya-Siddhānta itself advocates and gives formulae for two types of drik-karma-samskāras for viewing observable phenomena like eclipses, heliacal risings and settings, etc, but prohibits such steps for getting True Planets. It means siddhāntic True Planets are meant especially for astrology and are bound to differ from observed positions of physical planets. The latter is termed Drig-ganita, and Surya-Siddhāntic computation is called Saura. Another point is noteworthy : beeja correction is advocated only in mean planetary positions and not in manda-phala (equation of centre) or shighra-phala (conversion of heliocentric to geocentric positions) as some enthusiasts like Sāmanta Chandra Shekhara and his unnamed predecessor in beejopanayanādhyāya of Surya-Siddhānta tried in vain. Drik-karma-samskāra is different from Beeja-samskāra.

सिद्धांत की मृत्यु : ग्रह-लाघव और उत्तरवर्ती काल

Graha-lāghava by Ganesha Daivajna, based on base year as 1528 AD, removed mathematical operations and functions like sine, cosine, etc and provided handy tables for panchanga making based on crude metthods. Therefore, it became extremely popular and people lost interest in studying siddhānta. But the most important contribution of Graha-lāghava has not been highlighted : it is the first Indian text which proposed Drig-ganita should be followed in astrology. Before it, some isolated attempts were made, notably in Kerala, but with almost no success. Graha-lāghava succeeded in replacing non-Drik traditional siddhāntic method from a large part of India with its crude approach which was a mix of diverse siddhāntas without taking any help from empirical observation. Therefore, it was neither siddhāntic nor scientific ('scientific here means Drik or empirical). As a result of influence of Graha-lāghava, followers of Suryasiddhāntic Makaranda method omitted Mandaphalārdha correction since 16th century because Diwākara Daivajna advised that doing so will make planets Drik, ie, conform to empirical observations. Although this proposal was wrong, it was accepted, and thereafter siddhāntic panchāngas ceased to be made despite claims. Diwākara's brother Kamlākara Bhatta was a great mathematician and authored opposed Diwākara's proposal but few listened to him.

सूर्यसिद्धांत का सारांश

Extant version of Surya-Siddhānta has 14 chapters, and the 15th chapter "beejopanayanādhyāya" is given within 14th chapter now because its original verses were mutilated and changed in mediaeval period by someone and are of no use now, but Makaranda Sarani and Makaranda Vivarana gives the method of getting Surya-Siddhāntic beeja values. The extant chapters are :

1. The Mean Motions of Planets

2. The True Places of Planets

3. Three Questions (Direction, Place and Time)

4. Lunar Eclipse

5. Solar Eclipse

6. Projection of Eclipses

7. Planetary Conjunction

8. Conjunctions of Asterisms and Planets

9. Heliacal Risings and Settings

10. Elevation of Moon's Cusps (and Moon;s Risings and Settings)

11. Pāta (Certain Malignant Aspects of Sun and Moon)

12. Geography (and Cosmogony, Dimensions of the Creation)

13. Instruction of Jyotisha (The Armillary Sphere and Other Instruments)

Rāvaṇa Samhitā : unpublished but surviving in secrecy, Hindi translation online but unreliable, Sanskrit version in Deoria (UP) and Hoshiarpur (Punjab) but not made public; fragments at pther places too.

Garga Samhitā : unpublished but surviving.

Gotama Samhitā : manuscript in Telugu script.

Bhrigu Samhitā : one manuscript in Varanasi, other in Bangla made public but unpublished, rest scattered.

Bhrigu Nādi : three hundred verses available in manuscript, perhaps a fragment of Bhrigu Samhitā.

Bhrigu Yogāvali : in manuscript form.

Many Samhitā texts, esp of Bhrigu, Garga, Lomasha and Rāvana are believed to be present in the hands of individuals who hide them. Lomasha Samhitā had 60000 verses, but only 2% has been unearthed so far.

Most famous Samhitā text of later period is Brihat-Samhitā of Varāha Mihira which is almost encyclopaedic in nature.

Some of these Samhitā texts contain invaluable information about Jātaka not found in any known text. Perhaps "Samhitā" included Jātaka and Siddhānta originally, and division into separate skandhas is a later phenomenon. Now, Samhitā includes only following topics :

मेदिनी ज्योतिष

Yāmala Tantras

Narapatijayacharyā

Krishi Parāshara

Makaranda Prakāsha

Kādambini, etc

मुहूर्त

Muhurta Chintāmani is the most important extant text, based on ancient rules but incorporating mediaeval regional diversities as well.

वास्तु-शास्त्र

Vishvakarman-prakāsha

Mayamatam

Later texts

शकुन-शास्त्र

अन्यान्य (वृक्ष,रत्नादि,पशु, आदि)

होरा

Various Schools : ancient and modern

जातक : होरा-शास्त्र के मूलभूत सिद्धांत

Grahas and astrological attributes

Rāshis, Nakshatras and astrological attributes

Lagna, Bhāvas and significance

Shodasha-varga : methods of construction and techniques of using

Planetary strengths : Shadbala and vimshopaka-bala* Drishti (aspects)

Dashās : Moon based, and other types

Pada : Ārudha and Upapada

Argalā and Bādhaka

Kāraka

Svāmsha

Yogas

Āyu or Longevity

Varshaphala and Tājika

Ashtaka-varga

Sudarshana-chakra

Sarvatobhadra Chakra in Natal Horoscopy

Phalādesha :

** What Elements Constitute A Horoscope : It is wrong to assume that a horoscope is a single chart. A horoscope or Janma-patri is a group of charts and tables together with their interpretation and remedies of diagnosed problems. What elements should be included or excluded from a horoscope depends upon nature of the query. Normally, planetary table, Rāsi chart, Bhāva-chalita chart (D1 or first divisional or lagna-kundali), Navamāmsha chart or D9, Varsha-phala and Vimshottari-dashā table of D1 are considered to be essential parts of every horoscope, and extra elements are included if the query demands so. With the advent of computers, detailed horoscopes can be now produced with little effort.
** How to Interpret a Horoscope : In spite of help from computers, few astrologers can make predictions with confidence, because of the large number of charts and tables to be analyzed and also due to many wrong practices learnt from roadside books. Some astrological Yogas or combinations in one's own horoscope are essential for enabling one to become a successful astrologer. Yet, there are some essentials which must be followed for interpreting a horoscope, which are described in BPHS and Laghu Parāshari.

सामुद्रिक-शास्त्र

हस्तरेखा-शास्त्र

मुखाकृति-विज्ञान

अंग-लक्षणं

ग्रह-शान्ति

स्त्री-जातक

ज्योतिष में आधुनिक प्रयोग

ग्रह की परिभाषा में परिवर्तन

अयनांश की दो परिभाषाएं

वैदिक ज्योतिष की गणित और फलित शाखाओं में अन्य विवाद

ज्योतिष का अध्यापन और तत्संबंधी विवाद

विश्वविद्यालयों में ज्योतिष की मान्यता संबंधी विवाद

ज्योतिष-अध्यापन के प्रमुख केंद्र

विश्वविद्यालय और विद्यापीठ

स्वयंसेवी संस्थाएं

इन्टरनेट ग्रुप

गुरु-शिष्य परम्परा

बाह्य प्रभाव और उपयोग

Jain astrologers use Vedic Jyotiṣa. Islamic astrology in India has made important two-way interactions with native Jyotiṣa and some contributions from Islamic astrology has been accepted as a part of Vedic Jyotiṣa by many practitioners mostly in Tajik method of Varshaphala (annual charts). Purists reject all Islamic influences.

Some Indian scholars of Harvard University in USA started a website named 'Hindupedia' in which the starter article on "JYOTISH" can be accessed at : Overview of Jyotisha , which is being presented here verbatim in English (Hindi version is constantlu being updated) :

Definition

Jyotisha (ज्योतिष) , the traditional Indian system of astrology, was considered to be a sub-topic within astrology and as such, Jyotiṣa includes topics related to astronomy rooted in Vedic-Purānic tradition. It is often called Vedic Jyotiṣa by its practitioners and Hindu or Indian astrology by foreigners. Jyotiṣa is a Vedānga or an auxiliary text to the the Veda.

Shortest and best definition of Jyotiṣa is Karma-phala-vipāka-kāla-vidhānam, i.e., set of rules for timing of fruition of past actions. Jyotiṣa reasons out destiny in terms of Karma phala. Karma-phala loosely translates into the fruits of action and its predictions are reflections of karma phalas. All actions do not bear fruits instantly. Some results may be instantaneous while others may be deep and far reaching, often going beyond a single life. Jyotiṣa studies these obscure fruits of actions which we do not even remember. Destiny or prārabdha is that part of fruits of past actions which has become dominant and has pushed other fruits into backfround because they do not match with the dominant group of fruits which have resulted into one's birth in this world.

Origins

Jyotiṣa is a Vedānga (A vedānga is an auxiliary discipline to the Veda). The first ever record for Jyotiṣa is found in the Veda. The earliest reference to Jyotiṣa as a vedānga is found in the Mundaka Upanishad and Chāndogya Upanishada which mentions it as a distinct discipline. The first Vedic Yajna in Yajurveda is Darsha-paurnamāsa Yajna, which needed correct timing of tithis (eg, New Moon or Darsha, and Full Moon or Poornamāsa). Vedas are concerned with Yajnas which can be performed only at astrologically auspicious moments. Jyotiṣa has been referred to as the Eye of Veda because it makes the really eternal Wisdom or Veda tangible and perceivable by means of proving that the soul exists and takes rebirths, bearing its past Karma-phalas in the form of horoscopes.

Historical Evolution

Jyotiṣa in Vedic literature

Tāṇḍya Brāhmaṇa 23.23.3 mentions only 27, but the system of 28 Nakṣatras is also Vedic : Atharvaveda says "Abhijit me rāsatām puṇyameva" ; Taittiriya Brāhmaṇa 1.5.1 ; 3.1.1 ; 1.5.3.4 mentions Abhijit by name and gives 28 Nakṣatras. Hence, like modern Vedis Jyotiṣa, both systems of 27 and 28 Nakṣatras prevailed from the earliest times, 27 being used for general purposes and 28 being reserved for special uses.

Vedānga Jyotiṣa of Lagadha

Vedānga Jyotiṣa is not one but three different texts :

Yājuṣa-Jyotiṣa (44 verses, some versions have 49)

Ārcha-Jyotiṣa (36 verses)

Atharva-Jyotiṣa (163 verses).

Verse 2 of Yājuṣa-Jyotiṣa and verse 3 of Ārcha-Jyotiṣa define the subject of these treatises : finding the appropriate time for performing Yajñas ("Yajña-kālārtha-siddhayaye").

But Ārcha-Jyotiṣa (2nd verse) mentions Mahatmā Lagadha as the original composer of Ārcha-Jyotiṣa. It means the extant version was written in the post-Vedic period by someone else, while the original texts were composed by the sage Lagadha in Vedic period. Yajñas were performed during the Vedic Age and Yajña needed correct timing, which is proven by the name of first Vedic Yajña (Darśa-paurnamāsa ; Darśa means amāvasa).

Verse 5 in Yājuṣa-Jyotiṣa ("Mīnāt prabhṛti Raśayaḥ") and Verse 4 of Ārcha-Jyotiṣa are the earliest direct references to Raśi in ancient literature.

Atharva-Jyotiṣa is most detailed of these three texts, and gives detailed proofs pf phalita (predictive) Jyotiṣa in the Vedic period. Yajñas were performed for obtaining "phala". But only a tip of the iceberg has survived : verse 3 of Ārcha-Jyotiṣa says the motions of heavenly bodies are "completely" described in Ārcha-Jyotiṣa, but only 36 verses are extant now.

Jyotiṣa in Purānic and Epic literature

'Sarga' is an essential chapter in every Purāna, which describes the process and mathematics of Creation and Yuga-cycles, which are common to all ancient siddhāntas of Jyotiṣa. Some Purānas provide greater details about mathematical portions of Jyotiṣa, while important aspects and rules of Phalita Jyotiṣa and Parvādi are scattered in various Purānas. Nārada Purāna devoted greatest space to Jyotiṣa. Mahābhārata and Rāmāyana also contain many references to and uses of Jyotiṣa. For instance, Mahābhārata refers to the use of Sarvato-Bhadra Chakra which is an astrological tool fully described in ancient Yāmala Tantra literarure.

Jyotiṣa in Jain literature

Mediaeval Jyotiṣa Texts

Modern Jyotiṣa Texts

Extant Basic Texts

The main phalita text of Jyotiṣa is the Brihat Pārāshara Horā Shāstra (BPHS), originally called Pārāshari Horā, which belongs to the last phase of Dvāpara Age. Four chapters of Jaimini Sutra have also survived. Extant portions of Lomasha Samhitā and some other texts are also helpful in Horā, but BPHS remains the mainstay of Phalita. The most revered siddhāntic text of Jyotiṣa is Suryasiddhānta which states it was given by Lord Surya at the tail end of Krit Yuga. The earliest paurusheya (man-made) texts of Jyotiṣa , such as Panchsiddhāntika by Varāha Mihira, eulogize Suryasiddhānta as divine. There is a verse in Charana-vyuha which says that there were one lakh verses in Veda (only 20% has survived), one lakh is Mahābhārata (almost entirely survived), one lakh in Vyākarana (mostly lost) and four lakhs in Jyotiṣa. But even the magnum opum of Phalita Jyotiṣa, namely BPHS (Brihat Pārāshara Horā Shāstra) contains only four thousand (it is suspected to contain over ten thousand verses originally). Charana-vyuha is an ancient work and we have few texts of Jyotiṣa surviving from that time, and most of those surviving texts have been mutilated and distorted. Yet, enough remains to enable a person becoming a reasonably good astrologer according to modern standards, provided the conditions mentioned in BPHS for becoming a good astrologer are fulfilled : deft in Ganita and Horā as well as in Sanskrit grammar and Nyāya, intelligent, capable of deriving good inductions and deductions, knower of Desha and Kāla, and Jitendriya (brahmachāri). Few astrologers fulfill these conditions laid down by Sage Parāshara.

Key Concepts and Terms

Time System

How to measure Time depends on the purpose for which we need to measure Time. Hence, there are various Time-Systems.

Types of Time Systems

Yuga Cycles

Constituents of Time

Month : Solar and Lunar

Ahorātra

Ahorātra means the time from one Sunrise to next Sunrise at a given place on the surface of Earth. Literally, it means Day plus Night. It is not exactly equal to 24 hours, because Sunrise varies from day to day, while the modern measure of 'hour' is a constant defined on the basis of Atomic definition of a 'second' of time.

Ghati or Danda

Grahas and their Characteristics

PANCHĀNGA or Five Limbs

Moon is the fastest planet. Hence, elements related to motions of Moon are accorded highest priority in a religious almanac known as Panchānga (= "Five limbs") : Tithi, Karana, Rāsi, Nakshatra and Vāra.

Tithi

Tithi is Moon's Elongation or angular distance from Sun ; 12 degrees of elongation is equated to one tithi and 360 degrees or one full circle is one Luni-Solar Month, or in short Lunar Month of Hindus (Chāndra-māsa). Counting of tithis begin from New Moon to next New Moon, but counting of Luni-Solar months start and end with Full Moon, as the term "Poorna-māsi" implies. This system existed even in earliest Vedic era, as the very name of first Vedic yajna "Darshapoornamāsi" implies : Darsha means New Moon and Poorna-māsi means Completion of Month on Full Moon.

Karana

Karana is a subsidiary of Tithi, defined as exact half of a tithi.

Rāsi

Rasi and Nakshatra are interrelated and depend solely on Moon's absolute motion with respect to Fixed Sky.

Nakshatra

Vāra

Vāra is not a feature of Moon, but of Sun, and depends on topocentric Sunrise for a given place at earth's surface.

Additional Elements of Panchānga

How to Read a Panchānga

Subject matter and Uses of a panchānga

The word Panchānga means "Five limbs", i.e., Tithi, Karana, Nakshatra, Yoga and Vāra. All these five elements depend on motions of Moon and Sun and require high degree of accuracy due to fast motion of Moon. Moreover, these elements exert greater astrological influence than other planets. That is why religious almanac has come be labeled as 'Panchānga'. But a Panchānga should contain planetary data and table of ascendants for facilitating handy computation of horoscopes, and religious festivals and muhurtas (auspicious moments for diverse activities) are also provided in a normal Panchānga. A good Panchānga contains much extra related information as well and is published once a year. Beginning of religious year for publishing Panchāngas is not same for entire India, but beginning of white half of Chaitra is generally accepted as the start of religious (and traditional calendar) year by most Hindus. Sun's entry into nirayana (sidereal) Mesha is the mathematical New Year of Hindus.

Controversies about diversity of methods in making panchāngas

Other Key Concepts and Terms

Sub-divisions of Jyotiṣa

Vedic Jyotiṣa has two branches, Ganita (Siddhānta) and Phalita (Samhitā plus Horā). Ganita means mathematics, but in practice it does not include the calculations involved in making horoscopes and predictions, it is merely a synonym for Siddhānta in the parlance of traditional jyotishis. Phalita or predictive astrology has two main branches, Samhitā and Horā, which have many sub-branches as shown below. But in actual practice, Samhitā and Horā are enumerated as separate branches due to vast difference in their subject matter, and traditional taxonomy talks of three skandhas or divisions of Jyotiṣa : Siddhānta, Horā and Samhitā, and every good Jyotiṣi was expected to be adept in all three divisions of Tri-skandha Jyotiṣa-shāstra.

Siddhānta, which literally means "theory" (siddha+anta", ie "established conclusions") is traditional astronomy for special uses of astrology, which has many varieties broadly divided into two classes apaurusheya and paurusheya on whose basis later Tantra and Karana texts were derived.

Original apaurusheya Siddhāntas, 18 in number, propounded by sages or gods

Man-made or paurusheya siddhāntas, five ancient siddhāntas and another set of five later siddhāntas now used by traditional panchānga (a panchānga is the calendar or religious almanac makers).

Tantra (astrological) method and texts, different from philosophical Tantra

Karana method and texts

Drig-ganita or physical astronomy

Samhita , which includes :

Medini Jyotiṣa (mundane astrology) or predictive astrology of territorial regions and is used for predicting important events such as earthquakes, weather events like storms or rains, war, national politics and economy, prices (argha-kānda), etc, based on analysis of astrological dynamics in the horoscope of a territorial region of all sizes including whole world, and/or general transit events (graha-chāra).

84 Chakras (astrological) which are widely used in Medini Jyotiṣa as well as in Horā, such as Panch-shalākā or Sarvatobhadra chakras which originated in archaic Yāmala Tantras.

Vāstu-shāstra which is used for construction of houses, temples, forts and towns. Varāha Mihira included iconography and sculpture under Samhitā.

Shakuna-shāstra (omens)

Diverse topics like astrological and similar attributes of materials, trees, animals, regal attributes and items, etc.

Horā : predictive astrology of individuals, whose main branch is called Jātaka.

Jātaka which is used to analyze natal horoscopes (birth charts) known as janma-kundali. It includes Varshaphala. One of its branch Nasta-Jātaka studies those persons whose birth details are unknown.

Prashna (horary astrology) from which horoscopes based on the moment and a query are made. Prashna is also used to make hosocopes without birthdata in Nasta-Jātaka.

Sāmudrika shāstra studies palmistry, mukhākriti-vijnānam or study of facial features, anga-lakshanam or features of different parts of body, etc and correlate these things with planets of horoscopes.

Svara-shāstra

Strictly speaking, Horā-shāstra is based on birth time of the native and therefore Jātaka is the only true branch of Horā, but Prashna, Sāmudrika and Svara-shāstra are helpful in Horā esp when birth time is unknown. Even when birth time in known these disciplines help in removing errors and arriving at greater and better details.

SIDDHĀNTA

Ganita or Siddhānta skandha (branch) of Jyotisha is traditionally sub-divided into three sub-branches :

Siddhānta

It provides planetary calculations together all requisite formulas and their geometry from the beginning of Creation and provides details of all periods and sub-periods of entire Kalpa or Day of Lord Brahmā of 4.32 billion years, of which 1,955,885,111 years (in 2011 AD) have elapsed since the beginning of present Creation. In actual practice, no siddhānta is directly used for panchangas or horoscopes, because it is very difficult to make each and every computation from the beginning of Creation. Siddhānta is used only for creating Tantra and Karana texts for practical purposes.

Tantra

When planetary positions at the onset of current Yuga are tabulated and computations for succeeding years are made on the basis of these tables, the technique is called Tantra in Jyotisha. It has nothing to do with Tantra of philosophy. The only available Tantra text is Soma-Siddhānta which gives calculations from the beginning of Kaliyuga. Extant version of Surya-Siddhānta enables one to make computations from the beginning of Creation, but also gives planetary positions at the end of recent Krit Yuga (beginning of Tretā Yuga), hence it provided Tretā Yuga's Tantra method as well.

Karana

When starting point of Kaliyuga receded, Tantra method became difficult to use and Karana texts were created which used same method from some nearby year. Most famous Suryasiddhāntic Karana text is Makaranda Sārani, made for Shaka 1400 or 1478 AD. Its siddhantic version automatically updated for all eras is available in the form of free softwares : Kundalee and JHora-7.52 beta2 (constantly being updated).

Original 18 Siddhāntas

Mahabharata (1.70.43) defined siddhānta as "siddha-paksha-sthāpanam", i.e., establisheg the proven theory. It is said there were 18 ancient siddhāntas, but when ancient siddhāntas are enumerated from diverse sources excluding all texts after 400 AD, the list crosses 18 :

1. Brahma-siddhānta or Pitāmaha

2. Surya-siddhānta

3. Soma-siddhānta

4. Brihaspai-siddhānta

5. Garga-siddhānta

6. Nārada-siddhānta

7. Parāshara-siddhānta

8. Paulastya-siddhānta

9. Vasishtha-siddhānta

10. Vyāsa-siddhānta

11. Atri-siddhānta

12. Kashyapa-siddhānta

13. Marichi-siddhānta

14. Manu-siddhānta

15. Angirasa-siddhānta

16. Lomasha-siddhānta

17. Pulisha-siddhānta

18. Bhrigu-siddhānta

19. Shaunaka-siddhānta (Soma-siddhānta ?)

20. Chyavana-siddhānta

21. Yavana-siddhānta

Soma-Siddhānta is a Tantra variety of Surya-Siddhānta. Narada Purana gives details of planetary calculations which are perfectly in harmony with Surya-Siddhānta. Shaunka Horā states that Kaushika Viswāmitra learned accurate astronomy from Maya who first got Surya-Siddhānta. Shaunaka-Siddhānta is stated by some to be same as Soma-Siddhānta. Yavana-Siddhānta cannot be included among archaic Siddhāntas given by rishis or gods. Omitting Yavana-Siddhānta from the list and considering two Siddhāntas to be mere synonymns of other siddhāntas, the list can be reduced to the customary number 18. It is wrong to assume that there were 18 different Siddhāntas warring against each other. There was only one Siddhānta received by sages in different eras. As Surya-siddhānta states (chapter-1, verse-9), same Surya-siddhānta was given with "Kālabheda" in different eras. Varāha Mihira says Surya-siddhānta is the Siddhānta of Vedic god Savitā. At present, Surya-Siddhānta and Soma-Siddhānta are available in full, the latter being a Tantra version of the former, and Nārada-Siddhānta is available in some detail in Nārada Purana, which shows no difference with Surya-siddhānta. Brahma-Siddhānta is said to emanate from Lord Brahmā and is available in some detail in Brahma Vaivarta Purana, but shows no difference with Surya-Siddhānta. All other Siddhāntas have been completely lost because they were no longer needed, as is the case with Soma-siddhānta which was useful during initial centuries of Kaliyuga as its formulations prove but nobody touches it now. Hence, Surya-Siddhānta seems to be the basis of all Siddhāntas which were Tāntric manifestations of same Surya-siddhānta for different eras with respective beeja-samskāras.

Archaic Five Siddhāntas in Varāha Mihira's Panchsiddhāntikā

In his treatise Panchsiddhāntikā, Varāha Mihira mentions five Siddhāntas available in his era : Surya-Siddhānta, Paulisha-Siddhānta, Romaka-Siddhānta of yavanas, Paitamaha-Siddhānta and Vasishtha-Siddhānta, last two declared by him to be of no use in their extant forms, Surya-Siddhānta being the best. In Brihat Samhita too, Varāaha Mihira said that he used Surya-Siddhānta for computations.

Extant Five Siddhāntas used by modern traditional panchānga makers

All traditional panchanga makers use either of the following five Siddhāntas directly or indirectly : Surya-Siddhānta, Brahma-Sphuta Siddhānta of Brahmagupta, two Arya Siddhāntas of two Aryabhatas and Mahā-bhāskareeya of Bhāskara-i. Of these, Surya-Siddhānta is the only apaurusheya ancient text, others being beeja corrected versions made during 600-900 AD.

Comparison of other Siddhāntas with Suryasiddhānta

Suryasiddhānta versus Drik-siddhānta controversy

Beeja Samskāra

In the chapter on Mean Motions (verse-9) in Surya-Siddhānta, it is said that this siddānta is given by Lord Surya in different eras with Kāla-bheda, ie, with differences depending on Time. These differences must be in mean motions as the chapter's name suggests. Traditionally, such a difference is called "beeja-samskāra". Revolutions of a planet per Mahāyuga is called Yuga-bhagana. Texts give Yuga-bhagana in integers and fractional portion of Yuga-bhagana is added as beeja-samskāra. Makaranda-Vivarana by Daivajna Diwakara (17th century) gives the quantitative values of beeja-samskāra os various planets which were used in constructing Makaranda Tables in 1478 AD according to Surya-Siddhānta ("Shri Surya-Siddhānta matena…"). Unfortunately, many moderners not acquainted with traditional methods of panchānga makers now say that Surya-Siddhānta later became outdated and therefore beeja-samskāra was later introduced. Such a view is erroneous, because Surya-Siddhānta was never in conformity with physical astronomy and the divergence increases as we go back into past. Even after introducing beeja-samskāra, siddhāntic planetary positions do not come near to physical planets for any period of history. Ancients knew this problem. Vishni-dharmottara Purāna says : यन्त्रवेधादिना ज्ञातं यद्-बीजं गणकैस्ततः । ग्रहणादि परीक्षेत न तिथ्यादि कदाचन ।। I.e, for viewing eclipses &c, compute beeja according to observations from instruments &c, but never use this method for tithyādi. Nirnaya-sindhu, a respected text of Dharma-shāstra, also says : अदृष्टफलसिध्यर्थ यथार्कगणितं कुरु । गणितं यदि दृष्टार्थ तद्-दृष्ट्युद्भवस्सदा ।। I.e, use Surya-Siddhānta for getting astrological results. Surya-Siddhānta itself advocates and gives formulae for two types of drik-karma-samskāras for viewing observable phenomena like eclipses, heliacal risings and settings, etc, but prohibits such steps for getting True Planets. It means siddhāntic True Planets are meant especially for astrology and are bound to differ from observed positions of physical planets. The latter is termed Drig-ganita, and Surya-Siddhāntic computation is called Saura. Another point is noteworthy : beeja correction is advocated only in mean planetary positions and not in manda-phala (equation of centre) or shighra-phala (conversion of heliocentric to geocentric positions) as some enthusiasts like Sāmanta Chandra Shekhara and his unnamed predecessor in beejopanayanādhyāya of Surya-Siddhānta tried in vain. Drik-karma-samskāra is different from Beeja-samskāra.

Death of Siddhānta : Graha-lāghava and afterwards

Graha-lāghava by Ganesha Daivajna, based on base year as 1528 AD, removed mathematical operations and functions like sine, cosine, etc and provided handy tables for panchanga making based on crude metthods. Therefore, it became extremely popular and people lost interest in studying siddhānta. But the most important contribution of Graha-lāghava has not been highlighted : it is the first Indian text which proposed Drig-ganita should be followed in astrology. Before it, some isolated attempts were made, notably in Kerala, but with almost no success. Graha-lāghava succeeded in replacing non-Drik traditional siddhāntic method from a large part of India with its crude approach which was a mix of diverse siddhāntas without taking any help from empirical observation. Therefore, it was neither siddhāntic nor scientific ('scientific here means Drik or empirical). As a result of influence of Graha-lāghava, followers of Suryasiddhāntic Makaranda method omitted Mandaphalārdha correction since 16th century because Diwākara Daivajna advised that doing so will make planets Drik, ie, conform to empirical observations. Although this proposal was wrong, it was accepted, and thereafter siddhāntic panchāngas ceased to be made despite claims. Diwākara's brother Kamlākara Bhatta was a great mathematician and authored opposed Diwākara's proposal but few listened to him.

Summary of Surya-Siddhānta

Extant version of Surya-Siddhānta has 14 chapters, and the 15th chapter "beejopanayanādhyāya" is given within 14th chapter now because its original verses were mutilated and changed in mediaeval period by someone and are of no use now, but Makaranda Sarani and Makaranda Vivarana gives the method of getting Surya-Siddhāntic beeja values. The extant chapters are :

1. The Mean Motions of Planets

2. The True Places of Planets

3. Three Questions (Direction, Place and Time)

4. Lunar Eclipse

5. Solar Eclipse

6. Projection of Eclipses

7. Planetary Conjunction

8. Conjunctions of Asterisms and Planets

9. Heliacal Risings and Settings

10. Elevation of Moon's Cusps (and Moon;s Risings and Settings)

11. Pāta (Certain Malignant Aspects of Sun and Moon)

12. Geography (and Cosmogony, Dimensions of the Creation)

13. Instruction of Jyotisha (The Armillary Sphere and Other Instruments)

Rāvaṇa Samhitā : unpublished but surviving in secrecy, Hindi translation online but unreliable, Sanskrit version in Deoria (UP) and Hoshiarpur (Punjab) but not made public; fragments at pther places too.

Garga Samhitā : unpublished but surviving.

Gotama Samhitā : manuscript in Telugu script.

Bhrigu Samhitā : one manuscript in Varanasi, other in Bangla made public but unpublished, rest scattered.

Bhrigu Nādi : three hundred verses available in manuscript, perhaps a fragment of Bhrigu Samhitā.

Bhrigu Yogāvali : in manuscript form.

Many Samhitā texts, esp of Bhrigu, Garga, Lomasha and Rāvana are believed to be present in the hands of individuals who hide them. Lomasha Samhitā had 60000 verses, but only 2% has been unearthed so far.

Most famous Samhitā text of later period is Brihat-Samhitā of Varāha Mihira which is almost encyclopaedic in nature.

Some of these Samhitā texts contain invaluable information about Jātaka not found in any known text. Perhaps "Samhitā" included Jātaka and Siddhānta originally, and division into separate skandhas is a later phenomenon. Now, Samhitā includes only following topics :

Medini Jyotiṣa

Yāmala Tantras

Narapatijayacharyā

Krishi Parāshara

Makaranda Prakāsha

Kādambini, etc

Muhurta

Muhurta Chintāmani is the most important extant text, based on ancient rules but incorporating mediaeval regional diversities as well.

Vāstu Shāstra

Vishvakarman-prakāsha

Mayamatam

Later texts

Shakuna Shāstra

Misc (trees, minerals, animals, etc

HORĀ

Various Schools : ancient and modern

Jātaka : Elements of Natal Horoscopy :

Grahas and astrological attributes

Rāshis, Nakshatras and astrological attributes

Lagna, Bhāvas and significance

Shodasha-varga : methods of construction and techniques of using

Planetary strengths : Shadbala and vimshopaka-bala* Drishti (aspects)

Dashās : Moon based, and other types

Pada : Ārudha and Upapada

Argalā and Bādhaka

Kāraka

Svāmsha

Yogas

Āyu or Longevity

Varshaphala and Tājika

Ashtaka-varga

Sudarshana-chakra

Sarvatobhadra Chakra in Natal Horoscopy

Phalādesha :

** What Elements Constitute A Horoscope : It is wrong to assume that a horoscope is a single chart. A horoscope or Janma-patri is a group of charts and tables together with their interpretation and remedies of diagnosed problems. What elements should be included or excluded from a horoscope depends upon nature of the query. Normally, planetary table, Rāsi chart, Bhāva-chalita chart (D1 or first divisional or lagna-kundali), Navamāmsha chart or D9, Varsha-phala and Vimshottari-dashā table of D1 are considered to be essential parts of every horoscope, and extra elements are included if the query demands so. With the advent of computers, detailed horoscopes can be now produced with little effort.
** How to Interpret a Horoscope : In spite of help from computers, few astrologers can make predictions with confidence, because of the large number of charts and tables to be analyzed and also due to many wrong practices learnt from roadside books. Some astrological Yogas or combinations in one's own horoscope are essential for enabling one to become a successful astrologer. Yet, there are some essentials which must be followed for interpreting a horoscope, which are described in BPHS and Laghu Parāshari.

Stri-Jātaka or Feminine Horoscopy

MODERN INNOVATIONS in Jyotiṣa

Change in concept of Graha or planet

Two definitions of Ayanāmsha

Other controversies in Ganita and Phalita branches of Vedic Jyotiṣa

TEACHING of Jyotiṣa and controversies

Recognition of Jyotiṣa in universities and controversies

Chief centres of Jyotiṣa teaching

Universities and Vidyāpeethas

Voluntary Organizations and Institutions

Internet Groups

Ancient Guru-shiṣya tradition

External Influences & Uses

Jain astrologers use Vedic Jyotiṣa. Islamic astrology in India has made important two-way interactions with native Jyotiṣa and some contributions from Islamic astrology has been accepted as a part of Vedic Jyotiṣa by many practitioners mostly in Tajik method of Varshaphala (annual charts). Purists reject all Islamic influences.